Chapter 7 Defining Signatures

Configuring Signatures

Configuring Signatures

This section describes how to configure signature parameters, and contains the following topics:

•Signature Definition Options, page 7-6

•Configuring Alert Frequency, page 7-7

•Configuring Alert Severity, page 7-9

•Configuring the Event Counter, page 7-10

•Configuring Signature Fidelity Rating, page 7-12

•Configuring the Status of Signatures, page 7-13

•Configuring the Vulnerable OSes for a Signature, page 7-14

•Assigning Actions to Signatures, page 7-15

•Configuring AIC Signatures, page 7-17

•Configuring IP Fragment Reassembly, page 7-28

•Configuring TCP Stream Reassembly, page 7-31

•Configuring IP Logging, page 7-39

Signature Definition Options

The following options apply to configuring the general parameters of a specific signature:

•alert-frequency—Sets the summary options for grouping alerts.

•alert-severity—Sets the severity of the alert.

•engine—Specifies the signature engine. You can assign actions when you are in the engine submode.

•event-counter—Sets the event count.

•promisc-delta—Specifies the delta value used to determine the seriousness of the alert.

Caution We recommend that you do NOT change the promiscuous delta setting for a signature.

Promiscuous delta lowers the risk rating of certain alerts in promiscuous mode. Because the sensor does not know the attributes of the target system and in promiscuous mode cannot deny packets, it is useful to lower the prioritization of promiscuous alerts (based on the lower risk rating) so the administrator can focus on investigating higher risk rating alerts.

In inline mode, the sensor can deny the offending packets and they never reach the target host, so it does not matter if the target was vulnerable. The attack was not allowed on the network and so we do not subtract from the risk rating value.

Signatures that are not service, OS, or application specific have 0 for the promiscuous delta. If the signature is specific to an OS, service, or application, it has a promiscuous delta of 5, 10, or 15 calculated from 5 points for each category.

•sig-description—Your description of the signature.

•sig-fidelity-rating—Specifies the rating of the fidelity of signature.

•status—Sets the status of the signature to enabled or retired.

Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2

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Cisco Systems IPS4510K9 manual Configuring Signatures, Signature Definition Options
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IPS4510K9 specifications

Cisco Systems has long been a leading player in network security, and its IPS (Intrusion Prevention System) series is a testament to its commitment to safeguarding digital environments. Among its notable offerings are the IPS4510K9 and IPS4520K9 models, both designed to provide advanced threat protection for mid-sized to large enterprise networks.

The Cisco IPS4510K9 and IPS4520K9 are distinguished by their cutting-edge features that help organizations defend against a myriad of cyber threats. These systems utilize a multi-layered approach to security, integrating intrusion prevention, advanced malware protection, and comprehensive visibility across the network.

One of the primary characteristics of the IPS4510K9 is its high performance. It boasts a throughput of up to 1 Gbps, making it suitable for environments that demand rapid data processing and real-time responses to threats. The IPS4520K9, on the other hand, enhances that capability with improved throughput of up to 2 Gbps, accommodating larger enterprises with heavier network traffic. These models are equipped with powerful processors that support complex signature matching and can intelligently distinguish between legitimate traffic and potential threats.

In addition to performance, both models are designed with scalability in mind. They can be easily integrated into existing Cisco infrastructures. This facilitates a seamless enhancement of security without causing significant interruptions to ongoing operations. Moreover, they offer flexible deployment options, allowing organizations to operate them inline or out of band depending on their specific needs.

The Cisco IPS4510K9 and IPS4520K9 leverage advanced detection technologies, utilizing a variety of signature types and heuristic analysis to detect known and unknown threats effectively. They are equipped with real-time alerting and reporting capabilities, giving security teams immediate visibility into potential breaches and enabling them to respond swiftly.

Furthermore, both models support a range of management options through the Cisco Security Manager, allowing for centralized administration, streamlined policy management, and enhanced monitoring capabilities. Automated updates ensure the systems remain current with the latest threat intelligence, vital for staying ahead of evolving cyber threats.

In summary, the Cisco Systems IPS4510K9 and IPS4520K9 represent powerful solutions for organizations seeking robust intrusion prevention capabilities. With their high performance, scalability, and advanced detection technologies, these systems are essential tools in the ever-changing landscape of cybersecurity, providing enterprises with the peace of mind needed to operate securely in today's digital world.
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